Adjustable tool connection for platen presses



.Nov. 21, 1961 F. LAUFER ET AL 3,009,377

ADJUSTABLE TOOL CONNECTION FOR PLATEN PRESSES Filed April 5, 1957 Patented Nov. 21, 1961 3,009,377 ADJUSTABLE TOOL CONNECTION FOR PLATEN PRESSES Frdric Laufer and Ren De Trey, Prilly, near Lausanne,

Switzerland, assignors to J. Bobst and Son S.A., Prilly,

near Lausanne, Switzerland, a corporation of Switzerland Filed Apr. 3, 1957, Ser. No. 650,509 Claims priority, application Switzerland Apr. 16, 1956 3 Claims. (Cl. 83-699) The present invention relates to platen presses, and more particularly to presses of the type used for cutting out or shaping a material in sheet form.

conventionally fixed to the platens of such presses are plates or frames which may have very large dimensions and, thus, are very heavy. Since these plates are generally held against the platens in the vicinity of or by their edges, the result is that perfect seating of the tools against a platen is not possible, since the dimensions, weight and construction of these tools tend to produce sagging.

This can be prevented to a great extent by providing tools fixed to the associated platen. In fact, a fixing systern of this kind has already been proposed, using bolts extending through the platen. This approach is, however, deficient since it makes necessary dismantling operation whenever the tool has to be replaced or otherwise manipulated.

Accordingly, it is an object of the invention to provide improved means for the mounting of too-ls on the platens of presses and to do so while avoiding the complexities and deficiencies of known systems.

Briefly, to achieve the above and other of its objectives, the invention contemplates the provision of elements, preferably, incorporated into the associated press, for purposes of gripping the associated tool to cause the same to bear against the platen of a press.

The invention will next be explained in greater detail with reference to the accompanying drawing in which:

FIG. 1 indicates diagrammatically a press arrangement in which provisions of the invention can be embodied;

FIG. 2 illustrates, on enlarged scale, an embodiment of the invention adapted to be positioned according to line AB in FIG. 1;

FIG. 2A illustrates, on enlarged scale, the fastening of the tool to the platen according to lines AC in FIG. 1;

FIG. 3 illustrates a control provided by the invention seen in the direction of arrow F in FIG. 1; and

FIGS. 4 and 5 are operational diagrams.

In FIG. 1 the press comprises a mobile lower platen 1 which is lifted and lowered successively with respect to a fixed upper platen 2 connected with a body structure 3, the sheets to be worked being transported and guided between the platens by endless chains 4 which support gripper bars.

The lower tool has not been illustrated. The upper tool 5, however, is illustrated and is held against the upper platen 2 by its left-hand and right-hand edges with regard to the position illustrated, or else by 1ts front and rear edges or in the vicinity of such edges. The tool 5 will thus tend to sag and; generally, to bear imperfectly against the platen in central region thereof. This defect is found to exist even if grooves and ribs or studs adapted to engage in one another are used.

Thus, each time the platen oscillates the tool the latter bends in one and then in the reverse direction.

With high operating speeds, these bending actions, however slight they may be, impart to the tool a vibration which is harmful thereto and which is also harmful to the satisfactory holding and setting of the moulds or cutting devices which is carries.

The invention obviates this disadvantage by providing,

in the body of the structure of the press, at least one element which is adapted to be placed under tension in such manner as to exert a tractive force on a jaw which grips the tool so that the tool bears against the said platen.

FIG. 2 shows a portion of the upper platen 2, a portion of the body structure 3 of the press, and the central part of the tool 5 with a T-section rib 6. This structure is positioned along line AB of FIG. 1.

Rib 6, which is of small length and can be replaced by a stud, is slidable in a corresponding groove 6a in the platen 2, perpendicularly to the plane of the drawing.

It should be noted that the tool 5 has been illustrated in a simplified form which emits moulds o-r fillets, the make-ready pieces, and any protective metal sheet which might be used for covering the latter.

FIG. 2A illustrates a bolted arrangement whereby the ends of the tools are fastened to platen 2 by bolt 24 and nut 25 along lines AC of FIG. 1

Extending into the groove in the platen is a piston 7 which is slidable in a sleeve 8 and which is recessed at 9 so as to comprise a configuration similar to that of the groove. Thus, the piston forms a jaw adapted to coincide with the groove and thus receive the rib or stud 6 of the tool 5 with the object of retaining the same.

The piston 7 is connected to the upper part of the body structure 3 by a toggle lever whose two lever arms are constituted by two bars 10 and 11, the first being articulated to the piston 7 at pivot 12 and the second to a rod 13; their other ends are mutually articulated at pivot -14.

The rod 13 is adapted to move upwards and downwards in a specially shaped sleeve 15 which is held in the body structure 3. This movement takes place in opposition to the action of a compression spring 16 whose tension can be adjusted by means of a bolt 17 which is threaded on rod 13.

A vertical movement of the whole arrangement is made possible owing to the fact that the pivot 18 con necting the bar 1 1 to the rod 13 by means of a housing 18a (rigidly connected to bar 11) has some play in the sleeve 15, the said pivot extending through an elongated hole 19 in the said sleeve.

The dimensions of these members are such that, when the pivot 18 abuts against the upper part of the elongated hole 19, the opening of the jaw 9 of the piston 7 coincides with the groove in the platen 2, it being understood that the bars 10 and 1.1 are at this instant in alignment.

At pivot 14, where the said bars are pivotally connected to one another, a horizontal rod 20 is fixed to the pivot. In FIG. 2, and also as regards FIG. 1, it extends perpendicularly to the plane of the drawing. FIG. 3, on the other hand, shows rod 20 as seen from the side.

FIG. 3 shows, in side view, the bars '10 and 11 and also their pivot -14 and it will be seen that the rod 20 extends to a wall 3' of the body structure 3 of the press, the front side in the view shown in FIG. 1.

Situated outside the said wall is a handwheel 21 which, through the intermediary of the screw 22, is adapted to exert a pulling force in the direction of the arrow 23 on the toggle lever.

'It will be apparent that this handwheel is only a traction means given by way of example, and that it could be replaced, for example, by an eccentric or any other device adapted to fulfill the same functions.

The diagrammatic view in FIG. 4 shows the bars 10 and 11 in alignment between the spring 16 (here a draw spring for the sake of simplifying the drawings) and the jaw 9, which alignment corresponds to the position of rest of FIG. 2. A pulling effect can be exerted in the direction of the arrow 23 (for example, by means of the handwheel 2 1). It will be apparent (see position 3 of FIG. 5) that this will necessarily cause either the lifting of the jaw 9 or the deformation (compression in FIG. 2 or traction in FIG. 5) of the spring 16, so that the tool 5 will be gripped and made to bear against the platen. It is understood that the tool 5 peripherally engages the platen as well.

The position of the elastic member can of course vary; for example it could be incorporated in one of the lever arms of the toggle lever system or even in the rod 20.

It will be apparent that this rod, which can extend through the full width of the body structure of the press, could be connected to the pivots of a plurality of toggle lever systems acting, in a sense, in parallel on a plurality of T-section ribs or studs on the tool, which would thus be gripped and made to bear against the platen in two or three places at the same time.

In this case, it will be apparent that the elastic members such as member 16 should be provided in the proportion of one per toggle lever system, in order to compensate for the differences in play which would inevitably be present between one rib or stud and the next.

The object aimed at by the invention could also be achieved by other means than by toggle lever systems. For example it would be possible to connect the piston 7 to a simple rod extending in the direction A-B and which, in the vicinity of the end A would be connected to a device capable of exerting a pulling effect.

What we claim is:

1. In a press having a body supporting a platen against which is positioned a tool having opposite edges fastened to the platen and having a surface facing the platen; a

device for firmly urging the entire surface against the platen comprising: traction means located intermediate said opposite edges and extending through the platen, said traction means comprising a system of pivoted levers, one of said levers being resiliently pivotally attached to said platen and another of said levers being pivotally attached to said tool, a pivot coupling said levers at the free ends thereof and control means attached to said platen and being connected to the coupled lever ends for imparting lateral movement to said ends and thereby effecting endwise movement of said tool with respect to said platen.

2. A device as claimed in claim 1 comprising a lug on the tool for traction with said engagement means.

3. A device as claimed in claim -1, wherein the control means comprises a rod supported on the body and coupled to said pivot, the rod comprising a threaded portion, the device further comprising a handwheel engaging the threaded portion for adjusting the rod.

References Cited in the file of this patent UNITED STATES PATENTS 970,888 Conboy Sept. 20, 1910 1,306,726 Smith June 17, 1919 1,389,286 Anderson Aug. 30, 1921 1,563,940 Trenn Dec. 1, 1925 1,798,526 Fitzgerald Mar. 31, 1931 2,163,229 Knebel June 20, 1939 2,574,281 Olson Nov. 6, 1951 2,930,271 Whistler Mar. 29, 1960 

